1. Field of the Invention
The present invention relates to toy element set for constructional toy and, more particularly to such a toy element set, which comprises a plurality of gears that can be pivotally detachably fastened to planar elements and meshed on a plane or at right angles.
2. Description of the Related Art
Various constructional toys have been disclosed and patented, and have appeared on the market. These constructional toys are not simply made for children to play with. They can also be used as educational implement. Harvey""s U.S. Pat. No. 4,055,019 discloses a similar design, entitled xe2x80x9cConstructional toy and element thereforexe2x80x9d. However, these conventional constructional toys are not successful in toy market because they are not attractive to children. People may purchase these conventional constructional toys simply for educational purpose.
According to Harvey""s U.S. Pat. No. design, a planar element (polydron) is provided for use in building-up a model structure by hingedly and detachably connecting a plurality of such elements in edge-to-edge relationship. When using such planar elements to build up a model vehicle, as shown in FIG. 1, only particularly designed planar elements (the planar elements with a center axle hole) can be mounted with a wheel axle and a wheel. Further, the monotonous accessories of the constructional toy cannot attract children""s attention.
The present invention has been accomplished under the circumstances in view. According to one aspect of the present invention, the toy element set for constructional toy comprises square planar elements, coupling elements, and gears. Each square planar element has a center through hole. The coupling elements are adapted to connect square planar elements on a plane or at right angles. Each gear has a split shaft pivotally connectable to the through hole of one planar element. The diameter of the pitch circle of the gears is equal to the length of the diagonal of the planar elements. Therefore, the gears can be fastened to a respective planar element and meshed on a plane or at right angles. Further, each gear has a spacer flange at the inner side around the shaft and adapted to space the gear face of the respective gear from the corresponding planar element upon installation of the respective gear in the planar element. According to another aspect of the present invention, each gear has a coupling structure at the outer side for the connection of a barrel-like toy element, and a plug hole at the center for the connection of a rod member or crank handle.
When a number of gears installed in a model structure formed of a number of planar elements and coupling elements, a crank handle can be fastened to one gear and turned by hand to rotate the meshed gear train and other toy accessories attached to the gears of the gear train. Because the diameter of the pitch circle of the gears is equal to the length of the diagonal of the planar elements, a part of the teeth of each gear protrudes over the peripheral sides of the corresponding planar element in which the respective gear is installed. Therefore, the gears can be used as vehicle wheels in a model vehicle built up with planar elements and coupling elements.